基于高阶矩的非高斯风压极值计算

Calculation of peak non-Gaussian wind pressures based on high-order moments

基于采样时长较长的风洞试验数据,在Hermite多项式的基础上提出了计算风压极值的简化公式。采用Winterstein提出的近似解析式计算Hermite多项式的相关参数,根据风洞试验数据拟合得到了简化公式中的未知系数。将数据的极大值和极小值作为参考值,对拟合后的简化公式精度进行了评估。在极大值评估中,对比了简化公式与现有Hermite计算式的精度,其中后者的参数采用Yang等提出的近似解析式计算。研究结果表明,在不同采样频率、时距及风洞试验数据下,简化公式估计极大值精度较高,估计极小值则存在较大相对误差,但由于极小值数值较小,其实际差异不大。

Based on wind tunnel data with long sampling time,a simplified formula for the calculation of peak wind pressures was proposed on the basis of Hermite polynomial. After obtaining the related parameters of Hermite polynomial based on approximate analytical formulae proposed by Winterstein, the unknown coefficients in the simplified formula were obtained by fitting the wind tunnel test data. By regarding maximum wind pressures and minimum counterparts of the data as reference values,the accuracy of the fitted formula was assessed. During the evaluation of the maximum wind pressures,the accuracy of the simplified formula and existing formulae by applying Hermite polynomial was compared. In the current formula,the parameters were obtained by the approximate analytical formulae proposed by Yang et al. The results show that under different sampling frequencies,durations and wind tunnel test data,the simplified formula gives an accurate estimation of the maximum values,whereas the prediction for the minimum values is unsatisfactory. Nevertheless,the discrepancy for the latter case is insignificant as the absolute values of the minimum wind pressure are small.